The name for this world comes from its unusual mountain range, which strongly resembles its namesake from space. Skull is known as the "Trader's World." The local government is dominated by a council of "merchant princes" who indulge in risky speculative ventures. The entire local society is bent towards such dubious entrepreneurial ventures, and Ministry of Justice has an office on this world just to monitor its activities. The inevitable collapse of these risky ventures usually end up hurting the locals more than anyone else.

In addition to Skull Startown, other major settlements on Skull include Ukar, Rashge, and Shaar Town.

Skull is ruled by the Merchant Princes of Skull, a caste of citizens functioning effectively as a minor corporation and operating throughout the Marches. The Merchant Princes indulge in reckless speculative trading and ventures of dubious legality.